Field of Invention
The present invention relates to display devices.
Description of Related Art
Existing solutions for LED backlighting use either individually controlled LEDs, or a cluster of LEDs controlled as an individual unit. In each case, each LED is presented with a voltage and currents substantially identical to every other LED.
The diffused light output, or PSF, is essentially pre-determined by the emissive pattern of an individual LED. As shown in FIG. 1, a single LED 100 produces a fixed light emission patter (LED light) 110. The LED light is incident, for example, on optical films 120, resulting in the production of a shaped light output, or PSF 130 (pattern of diffused light). The PSF 130 is essentially constant, but may vary in intensity according to modulation or a brightness level energizing the LED.
A similar result occurs when using light source clusters. FIG. 2 is an example of an LED cluster 200 that results is a PSF 250. Here, the PSF 250 is mainly composed of an aggregate of light from the LED cluster 200. The PSF 250 has a different shape, but again is essentially constant with a varying intensity.